The role of this Core is to provide proteomics and mass spectrometry support for the investigators in the UAB Skin Diseases Research Center. This will be principally in the form of high-resolution separation of proteins in complex biological samples, coupled with mass spectrometry identification of proteins that comprise the biological samples generated by the various projects. Existing instrumentation m the UAB Comprehensive Cancer Center Mass Spectrometry and Proteomics Shared Facility will be used for the Skin Proteomics Core. Because this resource is heavily utilized, funding from the SDRC will enable investigators to obtain the technical help and expertise for their skin related projects. The Core will work with the SDRC investigators of the various projects in experimental design and sample generation, to ensure optimal analysis. Thus, the specific aims of this Core are (1) Optimization of protein recovery from cells and tissue specimens, (2) High resolution protein separation, (3) Isoelectric focusing/SDS-PAGE electrophoresis (on three different 2 nd dimension gel sizes), (4) Qualitative and quantitative gel image analysis via software (currently PDQuest [BioRad]) to identify differential protein expression and/or alterations in posttranslational modifications, (5) MALDI-TOF mass spectrometric identification of polypeptides based on database searching with tryptic mass fingerprints, (6) NanoLC-electrospray ionization mass spectrometry for peptide sequence analysis and analysis of covalent modifications Training in the experimental design and application of proteomics, and (7) use of protein databases and bioinformatics. Overall, the goals of the proteomics core are (1) to provide high-resolution two dimensional electrophoretic and/or chromatographic protein separations coupled with MALDI-TOF and other mass spectrometry analyses, and (2) to identify differences in polypeptide expression and/or modifications that may be the basis for various dermatological conditions being studied by the Center investigators.